Rarity

Rarity indicates the quality of a particular item, such as a weapon, armor piece, or shader.[1] There are five levels of rarity, each distinguishable by the color of the item icon background:[1]

Basic (white)

Uncommon (green)

Rare (blue)

Legendary (purple)

Exotic (gold)

Though players may carry as many exotic items as they like in their inventory, only one exotic armor piece and one exotic weapon may be equipped at the same time.[1] Exceptions are armor pieces with the "The Life Exotic" perk, which allows them to be equipped with another exotic.